HF Propagation Prediction Programs – and how to use themSteve NicholsG0KYA

Quick recapHF paths depend upon:

Time of dayTime of yearBand in useSolar Flux – EM radiationGeomagnetic Conditions

– Solar particulate outputThe path itself

- over land?- over sea?- how many hops?- daylight/night path?- TX/RX antenna gain?- a good dose of luck?

Quick recap

The FOT (Frequency of Optimum Transmission) gives the highest “probability” for the contact you want to make.

Basic history of prediction programs and models

Late 60s – Standard model of the ionosphere developed

Late 70s - IONCAP developed by George Lane from VOA then by Teters et al. for NTIA/ITS

1982 - MINIMUF developed for NOAA – did not include the earth's magnetic field and left out equatorial anomaly

Mid '80s – Raymond Fricker of BBC External Services releases MICROMUF and MAXIMUF, which included the role of the geomagnetic field and put in radiation angles

1993 VOACAP released, developed by George Lane improving the IONCAP model, corrected some algorithms, added new functions

2001 W6ELProp released

What Prediction Programs are out there?There are now really two basic types - based on:

The Raymond Fricker model - W6ELProp

The VOACAP model- VOACAP- VOAProp- HamCAP- WinCap Wizard- ACE HF- and others

If you hate computers you could use the charts from the ARRL ...

… or those from Gwyn Williams, G4FKH, on the RSGB's web site

Or you can produce your own hour by hour, band by band “book” (this one using VOAProp)

A word of caution!

Prediction programs offer a guide only

A word of caution!

Reality is usually more complex ….

W6ELProp

Free – getting a little old now, but very good and better at predicting 80m openings than VOACAP-derived programs.

See www.qsl.net/w6elprop/

W6ELProp

W6ELProp

W6ELProp

W6ELProp

W6ELProp

VOACAP

An industry standard and thought to be “one of the best”.

Very complex and hard to use.Lots of parameters can be changed/need to be set up

properlyGood for point-point predictionsHas to be installed before you can use some of the

other programs like VOAProp.

See www.voacap.com/

VOACAP

Critical! *

* See http://www.astrosurf.com/luxorion/qsl-soft-voacap3.htm and use smoothed sunspot numbers:

VOACAP

VOACAP

VOACAP Online – see http://www.voacap.com/prediction.html

VOAProp by G4ILO

Free – fantastic attempt at putting a graphical interface on VOACAP.

Can be adjusted easily to suit your stationShows IBP beaconsShows call areasCan be used for broadcast stations as well

See www.g4ilo.com/voaprop.html

VOAProp by G4ILO

VOAProp by G4ILO

HamCAP by VE3NEA

Another free front-end for VOACAP

Can also produce web pages

Can work with DXAtlas

Window is a little small and can’t be resized.

HamCAP by VE3NEA

HamCAP by VE3NEA

WinCap Wizard by Taborsoft

Free “lite” version– great graphical interface on VOACAP.

Can be adjusted just like VOACAPFull version costs $50

See www.taborsoft.com/wwizard/

WinCap Wizard by Taborsoft

WinCap Wizard by Taborsoft

ACE-HF

Costs $99Very good graphical representation of VOACAPCan handle beacons and “what’s open to where”

See http://www.hfradio.org/ace-hf/

ACE-HF

ACE-HF

In conclusion …

If doing contest planning ….

…. Work out what band is open to where and when…. Produce print outs on an hour by hour, band by band basis.

Failing that use a laptop or netbook

For ease of use VOAProp will work well on site

In conclusion …

Things to consider:

- The gain of your/other’s antenna + power

- Greyline openings

- Sporadic E

- Top Band openings

- Changing ionospheric/solar conditions during the contest